A few days ago, I ran into an ugly bug on different Scientific Linux 6.3 hosts (therefore this should also affect RHEL 6.3 and CentOS 6.3). The network hangs while the system itself is up, running and responsive. “Just” no network. Restarting the affected network interfaces is not enough, only a complete reboot brings the Intel 82574L-based network cards back to life (those NICs are onBoard on the Supermicro X9SCM-F and X8SIL mainboards of the affected hosts, so I can't simply change them). The logs showed entries like the following:

It seems that the ASPM of the Intel 82574L is broken. The corresponding Linux driver “e1000” therefore has this chip on its ASPM blacklists and disables it when the systems boots. However, there is some side effect which re-enabled the NIC'S ASPM state L1 after a network connection was established. This does not happen on all Linux flavors and kernel versions, but it happens at least on Scientific 6.3 with kernel 2.6.32-279.19.1.

Workaround: disable the NIC's ASPM after the system boots

A quick workaround is to manually disable the NIC'S ASPM after the system booted and the network “stabilized” (e.g. after a few minutes). The following command disables ASPM for a device:

setpci -s <ID-of-device> CAP_EXP+10.b=40

You can use lspci -vnn to get the device ID (first number of the line, 02:00.0 in the following example output):

I upgraded the OS of two servers last weekend. The planned downtime was also used to install LSI 3ware 9650SE-4LPML RAID controllers plus Battery Backup Unit (BBU). The BBU enables the controller to keep the write cache during a power failure. However, I was not able to create a RAID array with “Write Cache: enabled” on one system. I always got the message “Parameter not changeable” when the configuration was stored.

The solution was simple: wait. The Battery Backup Unit (BBU) on the system was not charged enough, therefore the controller denied enabling the “Write Cache” setting. So if you get the message “Parameter not changeable” when configuring a LSI 3ware Raid Controller, check if the “Write Cache” setting is the root of it and if a charging or failed BBU caused it. You can check the BBU status in the Controller BIOS Setup (I found “BBU Ready: no” in “Information→Battery”).

If you are searching for a powerful laptop to run Fedora 15 Lovelock on, have a look at the Lenovo ThinkPad T420 4180W1G/4180PH1.1) It simply rocks. All the internal peripherals are working out of the box (LAN, WLAN, graphics, sound, microphone, webcam, volume up/down and mute buttons, brightness control buttons, eSATA…). The Intel HD3000 processor graphics runs smoothly. Even no problems with external monitors up to a 2560×1600 resolution or when using both the built-in screen plus an external monitor connected to the Mini Dock Series 3 45N6678 docking station. The Intel Core i5-2520M CPU provides VT-d and VT-x. So everything is fine if you want to run VMs.

Downsides, pitfalls and notes:

The built-in speakers are really bad, even for a laptop.

The keyboard shows signs of cosmetic wear after a few weeks of usage.

Microsoft tax a.k.a. Windows 7 Professional 64bit. At least, you can use the pre-installed Windows to update the laptop's firmware with a few clicks before installing Linux. And the license may be used to run a Windows 7 VM (although the laptop is shipped without installation media, you can download the original Windows 7 ISO images from Digital River).

I can't tell if the fingerprint sensor and the Class 1 Smartcard Reader are working out of the box because I do not need nor did I test them. But the Smartcard Reader is at least recognized by the OS.

When using the Mini Dock Series 3 45N6678, the analog sound line-out is not passed-through (everything else works). This means you still have to use the laptop's headphone connector to connect speakers.

If you are looking for similar models out of the T420 family, you should know that some of them got two graphics adapters (a combination of Intel and NVIDIA). I don't know if these make any trouble or need special configuration because the 4180W1G/4180PH1 comes with Intel graphics only.

I just did the basic setup of my Nexus S (i0923 with SCLD). What should I say? It totally rocks. The pre-installed Android 2.3.3 is a pure revelation compared to the older versions running on my Motorola Milestone. All those small but annoying bugs seem to be gone. And most important: no more PITA regarding Android Updates.2) The phone comes with a micro-USB connector as my Milestone and most other new non-Apple phones do. Therefore there is no need to buy new USB-A→micro-USB-B cables.3)